1. Field of the Invention
The present disclosure relates to a method for controlling an electric power steering device and a device therefor. More particularly, the present disclosure relates to a method for adjusting a motor torque according to a driver's steering torque when the driver's steering torque is input in a situation where steering of a vehicle is adjusted using only the motor torque.
2. Description of the Prior Art
Generally, a steering device of a vehicle is a device for enabling a driver to change the proceeding direction of the vehicle according to the driver's will, and is a device that assists the driver to drive the vehicle in a desired direction by arbitrarily changing the rotational center of a turning wheel of the vehicle.
Recent power assisted steering devices assist steering power such that an operation of a steering wheel is heavy when a vehicle travels at a high speed and an operation of a steering wheel is light when a vehicle travels at a low speed. Various kinds of such power assisted steering devices are available, and electric power steering devices that assist steering force by using an electric motor are widely used. Electric power steering devices determine the size of assist steering force by controlling current supplied to a steering motor.
Meanwhile, studies on autonomous driving technology to minimize intervention of a driver have been actively carried out. For example, a cruise control system that minimizes a driver's intervention in controlling the speed of a vehicle been studied, and a technique that allows a vehicle to automatically steer by minimizing a driver's intervention in steering has been developed. In addition, studies on unmanned vehicles or autonomous driving techniques that exclude all intervention by a driver are also under way.
However, even when a driver's intervention in the speed or steering of a vehicle is minimized, it is necessary to maintain movement of the vehicle to be controlled by the driver's intervention when the intervention occurs due to a response to an emergency situation or restriction on the regulations. In such a situation, a control technique needs to prevent the heterogeneity or ambiguity of the movement of the vehicle at a time when the driver's intervention occurs.